13 mars 2012 - FAO recently launched projects in four Asian countries to step up defenses against influenza by moving beyond a focus on domestic poultry to instead address a range of threats posed by the ever closer mingling of humans, wild animals and, especially, livestock animals, and the potentially devastating influenza viruses they share.

On 23-24 February, FAO animal health experts from Bangladesh, China, Thailand and Viet Nam met with counterparts from national governments and research institutes, regional representatives from the World Organisation for Animal Health, the U.S. Department of Agriculture, the World Health Organization, the U.S. Centers for Disease Control, France’s International Research Center for Agricultural Development (CIRAD) and renowned universities and NGOs to hammer out the final details in the projects’ work plans over the next year. The inception workshop was titled “Determining the Role of Livestock in the Potential to Introduce a Pandemic Influenza Virus.”

The work falls within the larger umbrella of the USAID-funded Emerging Pandemic Threats (EPT) program, established in 2009 to expand upon the lessons learned in combating the global pandemic of H5N1 highly pathogenic avian influenza, which spread to over 60 countries before being reined in. HPAI however remains entrenched in six countries – and five of them are in Asia. The EPT program addresses the growing array of diseases emerging from the animal kingdom that threaten human health, not just avian influenza.

The influenza pandemic threat is however no less imminent, says FAO, which continues to monitor for any possible emerging influenza virus that could threaten human health, food sources and livelihoods. The newly adapted program, dubbed “EPT Plus,” will reflect the honing of FAO’s surveillance of influenza viruses over the years, which now increasingly focuses on monitoring for pathogens with pandemic potential in the mixing of crowded human populations with domestic pigs, domestic poultry, wild waterfowl and farmed ducks. In Asia, the crush of these skyrocketing populations could encourage the emergence of new strains of influenza. And as human populations grow and grow in wealth, animal populations are burgeoning too to keep up with the demand for meat and dairy products.

The widening scope reflects FAO’s tackling emerging diseases through a “One Health” approach. In One Health, the health of animals, people and the ecosystems that support them are inextricably linked, with even slight changes having repercussions for all of them.

Asia is home to 65 percent of the world’s pig population, with China alone accounting for 50 percent of the world total. China and Viet Nam are home to 75 percent of the world’s duck population. At the same time, there are seasonal migrations of wild birds that overwinter in these major animal production areas, often mingling with farmed wild birds and ducks that graze openly in rice paddies. On farms, chickens often mix freely with pigs. The close contact among all these species is a tinderbox that risks to produce a highly pathogenic influenza virus that one day could infect humans.

“If a pandemic avian influenza virus emerges in the Sahara, it’s never going to matter,” said Scott Newman, FAO wildlife epidemiologist and coordinator of FAO’s activities under EPT Plus. “But in areas where pigs, birds and people are all living increasingly closer together, that creates the perfect environment for avian influenza viruses to infect pigs, a host where viruses may swap genes and suddenly be passed on to humans in a much more lethal form.”

The number and range of potential hosts for influenza viruses living in daily direct contact/close proximity thus may encourage greater genetic diversity of influenza viruses, which multiplies the possible threats to human health, he said.

The program in the four countries will also monitor the major hubs of contact where, if people come into contact repeatedly over time with swine and poultry species, new viruses could emerge. Markets with live animals are one such hub.

The aim is to overlay various data to gain a deeper understanding of what drives the emergence of new influenza viruses with pandemic potential.